I remember taking a trip at 1:00AM with my dog Barney to go to the late night Walgreen's pharmacy for some pepto bismol. I knew for several reasons that he had an upset stomach and that some over the counter med would do the trick. However, it's generally NOT the thing to do. Identifying the reason for vomiting is often seen as a difficult task however, the reasons are generally few and the remedies are relatively simple in most cases. Here are some common solutions and problems.
1) Feed more and smaller meals thru the day. Some dogs will vomit bile because the stomach is empty and the stomach acids and digestive juices (bile) need some work to do. Try feeding smaller meals and make sure your dog has a small meal available right away in the morning.
2) Digestive issues that are not emergencies. Any bout of vomiting that last two or more days should be considered worthy of a trip to the vet. Many digestive disturbances are short lived and withholding food for 1-2 meals is often a good start. You may also mix some plain (unsweetened yogurt) in with the regular meal.
3) Yogurt is an excellent digestive aid and can be part of an ongoing part of a dog's diet. Low fat yogurt has more protein and whole yogurt has more fat. Many dogs prefer the whole yogurt but if your dog takes to the low fat, use it preferentially.
Other aids for digestive system challeneges include massage, acupressure, color/light therapy and herbs.